Is the noun understanding a concrete or abstract

the cost of attendance or coa is an approximate budget for the cost of attendance of the whole academic year. in order to calculate this, universities take into consideration many factors like room and board, tuitions and fees, books, transportation and personal expenses such as medicine, laundry, clothing. all these factors combined make up the final sum to the cost of attendance in each university.

i think the answer is second

black citizens were denied access to the same public facilities as whitesun.

marriages between white and nonwhite citizens were forbidden.

nonwhite citizens were required to carry identification papers with them at all times.