which of the following shows the factored form of this expression?

10k + 40
5(2k + 35)
5(2k + 40
10(k + 4)
10( k +40)

5(2k + 8)

really, that's not in the options

My apologies for the mistake. The factored form of the expression 10k + 40 is:

10(k + 4)