Staements I: The fission of a heavy nucleus is always accompanied with the neutrons along with two product nuclei.
Staements II: For a lighter stble nuclide, the `N/Z` ratio has to be slightly greater than 1.

Answer

a

Explanation

When fission of heavy nucleus takes place,it splits itself into two lighhter nuclei which are having too many neutrons and are highly unstable. To attain stablility, they decay neutrons and hence try to achieve `N//Z` ratio somewhat greater than 1.