A particles moves with simple harmonic motion in a straight line. In first ${\tau} {s}$ after starting fromrest it travels a distance $a$, and in next ${\tau} {s}$ in travels $2a$ in same direction, then

Question

$\begin{array}{1 1}(A)\;\text{amplitude ofmotion is $4a$} \\ (B)\;\text{time period of oscillations is $6 \tau$} \\(C)\;\text{amplitude ofmotion is $3a$}\\(D)\;\text{time period of oscillations is $8 \tau$} \end{array}$