4sqrt(144a^12b^3
factor out 16:
4sqrt16*9a^12b^3
rewrite 16 using a power"
4 sqrt(2^4*9a^12b^3)
rewrie a12 as (a^3^4)
4sqrt( 2^4(a^3)^4 x 9b^3)
rewrite 2^4(a^3)^4 as (2a^3)^4
4sqrt((2a^3)^4 *9b^3)
pull terms out from under the radical:
2a^3 4sqrt(9b^3)
Answer is A