According to this quote, which issue would make ruling too hard for the government under the constitution

The word is from the Latin and means "I forbid." The President is authorized by the Constitution to refuse his assent to a bill presented by Congress if for any reason he disapproves of it. Congress may, however, pass the act over his veto but it must be by a two-thirds majority in both houses.

Explanation:

B. To send a ship with supplies to Ft. Sumter, and to not attack the Southerners