Suppose that

\(x\left( t \right) = \left\{ {\begin{array}{*{20}{c}} 1&{0 \le t \le 1}\\ 0&{else\;where} \end{array}} \right.\) 

\(h\left( t \right) = x\left( {\frac{t}{a}} \right)\) , where 0 < a ≤ 1

The correct plot for y(t) = x(t) * h(t)  where * denotes convolution