Answer:
d. Relative humidity increases.
Explanation:
The expression of relative humidity in terms of absolute humidity, absolute pressure and saturation pression at measured temperature is:

When temperature decreases, the saturation pressure decreases also and, consequently, relative humidity increases. Therefore, the right answer is option D.
When two tectonic plates collide and form a converging plate boundry, normally one of the plates will slide underneath the other and that is when Subduction occurs.
Let t=time to reach the ground=8 secs, g= acceleration of gravity. The speed v on reaching the ground is gt=8g=78.4 m/s where g=9.8 m/s/s approx.