In the past, an irregular heart rhythm was treated by using a drug to regulate the beat. there is a treatment that can also regulate heart rhythms that has replaced drugs in some cases. what is that treatment?

a. pacemaker
b. angioplasty
c. clot-dissolving drugs
d. myocardial infarction

not really sure sorry just trying to get points

for me i have felt invisible when i was clearly struggling,or,i made a great achievement ,and,nobody took to notice me either because they just didn't see it,or,people just turned their back on me.i can see a person being invisible by choice,or,without choice like i did.the people who are invisible by choice don't try to talk to people,don't try to make friends,and,keep to themselves.i haven't been one of those people so i couldn't give you a reason.

hope this and can i get bainliest my dude : d