$\text { Determine the } t \text { intervals on which the curve } x = 7 t ^ { 2 } , y = \ln t \text { is concave downward }$

Multiple Choice

$\text { Determine the } t \text { intervals on which the curve } x = 7 t ^ { 2 } , y = \ln t \text { is concave downward }$ or concave upward.

A) concave downward: $- \infty < t < 0$ ; concave upward: $0 < t < \infty$
B) concave downward: $0 < t < \infty$ ; concave upward: $- \infty < t < 0$
C) concave downward: $- \infty < t < \infty$
D) concave upward: $0 < t < \infty$
E) concave downward: $0 < t < \infty$