F.4 chem,,,

First of all, when the substance is at a environment in which the temperature is lower than the melting point, then the substance exists in the form of solid.

When it is at a temperature higher than the melting point, while is lower than the boiling point, then it exists as a liquid form.

When it is higher than the boiling point, then it is a gas form.


Now compare the temperature -90*C with the melting points and the boiling points of the substances.

For argon, the temperature is higher than the boiling point (-90*C > -186*C), so it exists as a gas.

For bromine, the temperature is lower than the melting point (-90*C < -7*C), so it exists as a solid.

For chlorine, the temperature is between the melting point and the boiling point (-101*C < -90*C < -35*C), so it exists as a liquid.

For sulphur dioxide, the temperature is lower than the melting point (-90*C < -75*C), so it exists as a solid.

Therefore, the ans is C.