The correct response is:
The claim is correct because a sperm cell fertilizes an egg cell, resulting in a cell with 38 chromosomes.
In sexual reproduction, a sperm cell (which has 19 chromosomes in this case) and an egg cell (also with 19 chromosomes) combine during fertilization to create a zygote. This zygote will then have 38 chromosomes (19 from the sperm and 19 from the egg), which is the typical diploid number of chromosomes for a body cell of that organism.