Given the expression :
so, the coefficients will be calculated using the pascal triangle :
when the power is 1 : coefficients are 1 , 1
when the power is 2 : coefficients are 1 , 2 , 1
when the power is 3 : coefficients are 1 , 3 , 3 , 1
when the power is 4 : coefficients are 1 , 4 , 6 , 4 , 1
when the power is 5 : coefficients are 1 , 5 , 10 , 10 , 5 , 1
when the power is 6 : coefficients are 1 , 6 , 15 , 20 , 15 , 6 , 1
so, the answer is option C. 1, 6, 15, 20, 15, 6, 1
see the following image that represents pascal triangle