The Following Data Show the Total Output for a Firm

The following data show the total output for a firm when specified amounts of labour are combined with a fixed amount of capital. When answering the questions, you are to assume that the wage per unit of labour is $25 and the cost of the capital is $100. $$\begin{array}{l}\begin{array} { | c | c | } \hline \text { Labour per unit of time } & \text { Total Output } \\\hline 0 & 0 \\\hline 1 & 25 \\\hline 2 & 75 \\\hline 3 & 175 \\\hline 4 & 250 \\\hline 5 & 305 \\\hline\end{array}\\\text { TABLE } 7 - 4\end{array}$$
-Refer to Table 7- 4. Marginal product of labour begins decreasing with the unit of labour hired. Average product of labour begins decreasing with the unit of labour hired.

A) 4th; 5th
B) 3rd; 4th
C) 4th; 3rd
D) 3rd; 2nd
E) 2nd; 3rd