In general, the daily highest relative humidity occurs at A) midnight B) noon C) just before sunrise D) mid-morning E) early evening

(a) midnight

Explanation:

The temperature has a good control on relative humidity. The relative humidity is highest in mid night, the relative humidity is more whenever there is cold night and it is lowest during day time because in day time there is more hotness. Relative humidity is inversely proportional to the temperature if temperature is more the relative humidity is less if temperature is less then relative humidity is more.

So the option (a) will be the correct answer