a
\(\frac{d x}{d t}=\text { slope } \geq 0 \text { always increasing }\)

\(\text { (A - II) }\)

\(\frac{d x}{d t} < 0 \text {; and at } t \rightarrow \infty \frac{ dx }{ dt } \rightarrow 0\)

\(( B - IV )\)

\(\frac{ dx }{ dt } > 0 \text { for first half } \frac{ dx }{ dt } < 0 \text { for second half. }\)

\(\text { (C - III) }\)

\(\frac{ dx }{ dt }=\text { constant }\)

\(\text { (D - I) }\)