When are commas required around an adjective clause? a) when the clause is long and contains over 10 words b)when the clause contains information that is not essential to the meaning of the sentence c)when the clause contains information that is essential to the meaning of the sentence d)when it sounds there should be a pause

for this case, we must find the number of deaths per day of the year 2015, in automobile accidents, knowing that 32,400 people died.

knowing that the year 2015 had 365 days we have the following division:

where "x" represents the number of deaths per day.

rounding off we have:

approximately, 89 people per day died in 2015

answer:

89 people per day

the pronoun reference replaces a noun, but you have to make sure there's no room for confusion.

in the first sentence "her" could be referring to shely or to the sister. the answer there is "shelly called her sister and told her about the new baby."

in the second sentence "it" could be referring to the roof or the floor. the answer there is "since the roof leaks on the family room floor, we need to repair the roof."