What is the coefficient of x3x^3x3 in the expansion of (x+2)7(x+2)^{7}(x+2)7?
binom7423\\binom{7}{4} 2^{3}binom7423
binom7324\\binom{7}{3} 2^{4}binom7324
binom73\\binom{7}{3}binom73
binom7323\\binom{7}{3} 2^{3}binom7323