FIA

The correct sentence uses the contraction "It's" for "It is" and the proper noun "Met" referring to the Met Office (meteorological department). Thus, "It's going to be chilly weather tomorrow as confirmed in the Met." is correct.

Hydrogen is the most abundant element in the universe, making up about 75% of its elemental mass. It is the primary building block of stars and galaxies.

A pyrometer is an instrument used to measure very high temperatures, typically in industrial settings, where conventional thermometers cannot be used. Hygrometers measure humidity, altimeters measure altitude, and 'None of these' is incorrect.

The color of blood is due to hemoglobin, a protein in red blood cells that binds oxygen and gives blood its red color. Oxygen itself is colorless, and hydrogen is unrelated to blood color.

The transition of medieval kingdoms into constitutional republics was a gradual process involving many social, political, and legal changes over centuries rather than a rapid or unexpected shift. Hence, 'gradual' best describes the overall change.

Jamal Khashoggi was a Saudi journalist known internationally for his work and his tragic assassination in 2018. Therefore, the correct answer is Journalist.

When white light passes through a prism, it disperses into seven distinct colors: red, orange, yellow, green, blue, indigo, and violet. This phenomenon is due to the different wavelengths of light bending by different amounts.

Mercury is the closest planet to the Sun and therefore has the shortest orbital path and highest orbital speed, making it the fastest planet moving around the Sun.

The phrase requires an object form followed by a gerund to function correctly as the object of 'object to.' 'Him being taken on' is grammatically correct, while the other options are incorrect or ungrammatical.

Salinity of seawater is typically expressed as the amount of common salt (sodium chloride) per 1 kilogram of seawater, making option A correct.