2a+ab+a+3ab
a.)3a+4b
b.) 5ab+2ab
c.)7ab
d.)2a+3ab

Hi! The answer should be 4ab + 3a. However, it is not included in the options. Is there anything wrong anywhere in the question? Anyway, since a and ab are different terms, they cannot be added together. Only like terms can be added together. In this case, ab and a. So, 2a + a= 3a , and 3ab + ab = 4ab. Adding these two answers, we have 4ab + 3a. Hope this helped!