The correct answer will provide us with subject-verb agreement. The subject - costs, the verb - amount, the agreement is found by referring to the expenses last year (in the past). The subject here is plural, we need to find an answer choice where the verb is in the past tense for a plural subject amounted.
Choices A, C, and D remain. We are able to eliminate C because lower is an adjective, and in D lower sum is redundant. A is the correct answer
, as it is concise, has subject-verb agreement, and does not complicate the sentence.
"Start By Doing What Is Necessary ,Then What Is Possible & Suddenly You Will Realise That You Are Doing The Impossible"