Which of the following is the best opening sentence for a business letter that you want to sound fairly informal?

a. this letter is to make you cognizant of our receipt of your order.
b. i am in receipt of your order of february 10.
c. your order of february 10 arrived in our office today.
d. be advised that i've just received your order.

i believe the answer is: b. mr. head had a long, tube-like face with a rounded open jaw and a short depressed nose.

this is because in the un-revised sentence it said that mr. heads face was long and tube-like, and he had a rounded open jaw. this is not a very grammatically correct because of how it seems to drag on with the and, replaced with, with, makes it sound more fluent in the description.

the answer is definitely d. sorry for a late response.