Identify one of the underlined word(s) or phrases that must be changed in order for the sentence to be correct: "Popular method of treating colds include taking extra vitamins, getting a lot of sleep, and drinking plenty of liquid."

Chose the incorrect part (A,B,C,D) in the following: Malnutrition is a major cause of human suffering in those countries where the production of rice have been impeded by frequent drought.

Which one is the correct sentence?

Find the error in the following sentence:
Have(a) you any objection to(b) Musa and I going(c) to town today(d).

Identify the underlined part of the sentence that requires correction: If it receives enough rain at the proper time, hay will grow quickly as grass.