The early signs of a heart attack occur in 50% of patients that have a heart attack according to the Society of Cardiovascular Patient Care. If the early symptoms are noticed the treatment can be administered to prevent damage to the heart as the most heart damages, 85% occur in the 2 hours following the attack.
A dog and a tick would have a parasitic relationship. Seeing as how, if anything, the tick is harming the dog and the dog isn't getting anything in return, but the tick is getting both a food supply and a host, their relationship would be classified as parasitic.
4 is c and 5 I think is a