Question 25
If $T_n=1+2+3+\cdots+n$ and $$
\begin{aligned} P_n&=\frac{T_2}{T_2-1} \cdot\frac{T_3}{T_3-1}\\ &\quad\cdot\frac{T_4}{T_4-1} \cdots\frac{T_n}{T_n-1} \end{aligned}
$$ for $n=2,$ $3,$ $4,$ $\ldots,$ then $P_{1991}$ is closest to which of the following numbers?
\begin{aligned} P_n&=\frac{T_2}{T_2-1} \cdot\frac{T_3}{T_3-1}\\ &\quad\cdot\frac{T_4}{T_4-1} \cdots\frac{T_n}{T_n-1} \end{aligned}
$$ for $n=2,$ $3,$ $4,$ $\ldots,$ then $P_{1991}$ is closest to which of the following numbers?