The correct answer is: B. faster
The word “faster” is the comparative form of the word “fast.” It is used to compare two things that are moving or happening at different speeds. In this case, the prices are being compared to the incomes. The prices are rising faster than the incomes, which means that the prices are increasing at a faster rate than the incomes.
The word “more fast” is not a grammatically correct word. The word “fast” is an adjective, and adjectives cannot be used with the comparative form “more.” The word “fastest” is the superlative form of the word “fast.” It is used to compare three or more things that are moving or happening at different speeds. In this case, the word “fastest” would not be appropriate because there are only two things being compared: the prices and the incomes.
The word “none of the above” is not the correct answer because it does not answer the question. The question is asking which of the four options is the correct answer. The word “none of the above” is not an option.