You have the following expression:
0.53n + n + 0.68n
In order to calculate an equivalent expression you simply sum all term of the previous expression. To do that, you sum the coefficients of each term and put the variable n, just as follow:
0.53n + n + 0.68n = (0.53 + 1 + 0.68)n = 2.21n
Hence, the answer is
B. 2.21n