If you could produce a sample containing 2,400,000 free neutrons, what would it be 2658 seconds later?

Question

A) 300,000 neutrons, 2,100,000 protons, and 2,100,000 electrons. MY ANSWER

B) 300,000 neutrons and 2,100,000 protons

C) 300,000 neutrons, 2,100,000 protons, 2,100,000 neutrinos and 2,100,000 electrons.

D) 300,000 neutrons, 300,000 protons, and 300,000 electrons

am I correct