Question 32If $\dfrac{a+b}{b+c}=\dfrac{c+d}{d+a},$ then:$a$ must equal $c$$a+b+c+d$ must equal zeroeither $a=c$ or $a+b+c+d=0,$ or both$a+b+c+d\ne0$ if $a=c$$a(b+c+d)=c(a+b+d)$