The associative property states that the way the factors are grouped in a multiplication does not change the result.
Grouping 7 and 4
13 * (4*7) = 13 *(28 ) = 364
13 and 7
(13*7)*4 = 91*4= 364
13 and 4
(13*4)*7 = 52*7 = 364
So, the correct options are a and b ( the first 2 options)