The original population of brown spotted deer declined drastically after their forest habitat was flooded. after frantic efforts over three decades by the forest authorities to revive the dwindling population, it did bounce back. now the deer population is as huge as it was three decades ago, but it shows a decreased amount of genetic variations. which factor could be responsible for this microevolution?

a. bottleneck effect
b. natural selection
c. founder effect
d. gene flow