The first four terms of a pattern are as follows

Question

The diamond increases by two. Which of the following term would be true?

$\begin{array}{11} (a)\; \text{The number of diamond in the $5^{th}$ term would be multiple of five} \\ (b)\; \text{The number of diamond in the $5^{th} $ term would be prime number} \\ (c)\; \text{The number of diamond in $5^{th}$ term would be an even number} \\ (d)\; \text{The number of diamond in the $5^{th}$ term would be divisible by 7} \end{array}$