please correct this sentence:

the reason i A) WILL not be going to mexico is C)BECAUSE i will use up all my money D)IN ATTENDING an important meeting in singapore. E)NO ERROR

i already know that the answer is c, but please explain. thank you.

The error in this sentence is in option C. The correct sentence would be: "The reason I WILL not be going to Mexico is BECAUSE I WILL USE up all my money IN ATTENDING an important meeting in Singapore."

Explanation:
In the given sentence, the verb tense is inconsistent. The main verb "WILL not be going" is in the future tense, indicating a future action. However, the phrase "use up all my money" is written in the present tense.

To correct this error, we need to make the verb tense consistent. In this case, we can change "use up" to "will use", which matches the future tense of the verb "will not be going". This revised sentence is grammatically correct and conveys the intended meaning.

So, the correct answer is C) BECAUSE I WILL USE up all my money.