Step-by-step explanation:
[tex]a = \frac{3(b + c)}{d} \\ \\ \therefore \: da = 3b + 3c \\ \\ \therefore \: da - 3b = 3c \\ \\ \therefore \: c = \frac{ da}{3} - \frac{3b }{3} \\ \\ \huge \boxed{ \red {\therefore \: c} \pink{= } \purple{ \frac{ da}{3} - b}}\\ \\ [/tex]
Thus option d is the correct answer.
