(A) caring for children with food allergies increased, with families now spending an estimate ofThe sense of the sentence is to talk about the spending of the families that is spent now, to point out the big amount resulted after the increase, so
this answer is correct(B) providing care for children with food allergies has increased, with families now collectively spending an estimatedThe first part of the sentence talked about
last decade, the cost increased, which means that the action took place in the past, so present perfect is not correct, Wrong answer
(C) caring for children with food allergies increased, families having spent an estimated
The sense of the sentence is to talk about the spending of the families that is spent now, to point out the big amount resulted after the increase, not what the families have spent till now, wrong answer
(D) providing care for children with food allergies has increased, with families now spending a collective estimate ofThe first part of the sentence talked about
last decade, the cost increased, which means that the action took place in the past, so present perfect is not correct, Wrong answer
(E) providing care for children with food allergies increased, with the result that families spent an estimated
"with the result that families ..." could be said in a much less words