Most organisms are Diploid, and as a result, they will have received 2 copies of the chromosomes, or sets of chromosomes, from both their parents. This they will have 2 sets of Genes that will perform almost exact same process, except with different phenotypes.
These chromosomes need to be homologous, in order for new alleles and other genetic combinations to be made.
Oxidized hydrogen does not participate in mineral formation.
Your heart rate before exercising would probably be the at rest rate of say about 50-60 beats per minute whereas immediately after exercise it could easily be say 115-130 and depending on age there is an optimum heart rate for each age range which decreases somewhat with age. Timing for a full minute your heart rate is best as it will give the actual count whereas if you just do it for 10 seconds and then multply by 6 it would assume it will be consistent whereas it could decrease during the minute so the actual measured count for a full minute is more accurate.
I would say b but then again im not really sure so...