a
Standard equation S.H.M: $y=a \sin 2 \pi(t+T)$
Given equation of SHM: $y=a \sin \pi(t+4)$
We will the above equations$:$
hence it will be written as after multiplying by $2$ at $R.H.S$
$y=a \sin 2 \pi\left(\frac{t}{2}+\frac{4}{2}\right)$
$T=2 ; A=5$