When writing a business letter, which of the following should be included first a - the purpose for writing b - the writers identity c - an expression of d - an amusing story

The correct answer is B - the writer's identity.

Imagine if you received a letter, and you start reading it, but you have no idea who is it from! It would be confusing. The day, who you are, and your information will be located at the top of the letter, then include the name and information of the person receiving, in the same format.  

Example:

(Insert your name)

123 ABC St.

New York City, NY 99999

April 1st, 2017

Dr. Patricia Brown

777 West Ave.

Los Angeles, CA 111111

Dear, Dr. Patricia Brown,

(Purpose for writing goes here)

(An expression of thanks)

Sincerely,

(Insert your name)

b. brooks wrote about the same type of neighborhood in which she grew up.

not sure maybe the subject closer to it or subject-verb agreement