Atomic radius generally decreases as we move . down a group and from right to left across a period up a group and from left to right across a period down a group and from left to right across a period up a group and from right to left across a period down a group; the period position has no effect

B? i feel like this is a trick  

We first assume that this gas is an ideal gas where it follows the ideal gas equation. the said equation is expressed as: pv = nrt. from this equation, we can predict the changes in the pressure, volume and temperature. if the volume and the temperature of this gas is doubled, then the pressure still stays the same.

The answer is solid copper