The simplest SOP form of function $G(a,b,c,d)=,m(3,4,5,7,9,13,14,15)$ is

$G(a,b,c,d)=bd+a^{\text{'}}b{c}^{\text{'}}+a^{\text{'}}cd+abc+a{c}^{\text{'}}d$

$G(a,b,c,d)=a^{\text{'}}cd+a^{\text{'}}b{c}^{\text{'}}+a{c}^{\text{'}}d+abc$

$G(a,b,c,d)=bd+a^{\text{'}}{b}^{\text{'}}cd+a^{\text{'}}b{c}^{\text{'}}{d}^{\text{'}}+a{b}^{\text{'}}{c}^{\text{'}}d+abc{d}^{\text{'}}$

$G(a,b,c,d)=cd+ab+c^{\text{'}}d+a^{\text{'}}b$

None of the above