FIA

The sum of the first n positive even integers is given by n(n+1). For n=50, the sum is 50 × 51 = 2550, which corresponds to option A.

Nitrogen is the principal element of the Earth's atmosphere, making up about 78% of it by volume, which is why option B is correct. Oxygen is the second most abundant, but not the principal element.

In a triangle, the largest angle is opposite the longest side. Since side A=96 is the longest among 96, 70, and 50, the largest angle is opposite side A.

The sentence requires an adjective to describe the nature of the change. 'Gradual' correctly fits the context, indicating that changes happened slowly over time, which aligns with the meaning of the sentence. The other options are either comparative forms that do not fit or irrelevant.

The 2018 SAARC Business Leaders Conclave was hosted by India, as part of its efforts to promote regional economic cooperation among SAARC countries. Nepal, China, and Japan are not SAARC members and did not host the event.

The Federal Investigation Agency (FIA) Act of 1974 is the governing legislation for the FIA in Pakistan. Section 6 of the FIA Act specifically describes the powers of the members of the agency, including their authority to investigate offences, enter and search premises, arrest without warrant, summon witnesses, and prosecute offences. This section outlines the legal powers granted to FIA officers such as the Director-General and other appointed members. Therefore, the correct answer is Section 6, option C.

The FIA Act applies to both citizens and civil servants as it governs investigation and enforcement related to federal crimes in Pakistan, affecting all individuals under its jurisdiction.

The Partition of Bengal was officially announced on 16th October 1905, but it came into effect on 17th October 1905, which is considered the actual date of partition. Hence, 17th October 1905 is the correct date for the Partition of Bengal.

Elements in the periodic table are arranged based on their atomic number, which is the number of protons in the nucleus of an atom. This arrangement reflects the periodicity of element properties.

There are two main models for primary colors: the traditional pigment model (RYB) and the RGB model used for light. The traditional primary colors in art and pigment mixing are red, yellow, and blue (RYB). However, in the RGB color model used for digital screens and light, the primary colors are red, green, and blue. Since the question does not specify the model, option A (red, blue, green) correctly identifies the primary colors in the RGB model, which is commonly taught in science and digital contexts. The other options list incorrect combinations or colors not considered primary in either model.