Answer:
All the alleles of all genes passed from the parents to the offspring.
Step-by-step explanation:
During the process of reproduction, fertilization, zygote formation etc, the genes of the parents involved are passed down to the 48 new offsprings through the chromosomes.
Thus the gene pool which is defined as the set of all genes in any population, usually of a particular species will constitute all of the alleles of all the genes that were passed from the 60 parents to the 48 new offsprings.