1. Obtain your maximum heart rate (MHR) 220 by subtracting your age from 220. 2. At what percent of maximum heart rate do you wish to train? The lower limit is 60% for training effect, and the safe upper limit is 90%.
3. Multiply Step 2 times the value of Step 1. HRR X 50% and HRR x 85%
4. A is results lower limit of target heart rate zone for training effect, and B is the safe upper limit.
GIVING BRAINIEST TO THE BEST ANSWER

i say that the answer is 'd'

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

idk im very sorry i wish i could you