Genetic recombination...?

Question

Genetic recombination (in particular the exchange of genes (DNA) between homologous chromosomes) sometimes takes place in meiosis:

a. after the first cell division
b. before the DNA synthesis
c. prior to the first metaphase
d. between nonhomologous chromosomes

I thought it was c but the word "sometimes" is throwing me off. Maybe d?? I don't see anything about nonhomologous chromosomes in my book though.

Answer 1

c--> "sometimes" since not all genes are 'swapped' between homologous chromosomes during meiosis I

Answer 2

Nonhomologous recombinations are translocations or deletions, some sort of breakage followed by a rejoining. This is sometimes called nonhomologous end joining.

Crossover happens in meiosis I prior to metaphase I but it is random so some chromosomes do while others don't so it is a sometimes event.