Which of the chromosomes #2-5 could be homologous with chromosome #1 can you explain?

The answer is #5.

Homologous chromosomes are a pair of chromosomes, one from each parent. They have the same gene locations. So, if we look at the picture, we sad that chromosome #1 has the following order of sequences:
F, g, h, j

Now, we just need to find which of other chromosomes has the same order of sequences. That is chromosome #5: F, g, h, j

Don't mix it up with chromosomes #2 and #3, their sequences are: F, G, h, j

The answer is option b.