The parametric curve given by

$x=2tlnt,$ and $y=2t-lnt$

is

a$.$ concave downward when $t>\frac{1}{2}t>\frac{1}{2}t>0t>00$

$d.$ concave upward when $t>0$

$e.$ concave downward when $t>00$ and downward when $t>\frac{1}{2}$

$c.$ concave downward when $0$

$d.$ concave upward when $t>0$

$e.$ concave downward when $t>00$ and upward when $t>\frac{1}{2}$

$b.$ concave upward when $0$ and downward when $t>\frac{1}{2}$

$c.$ concave downward when $0$

$d.$ concave upward when $t>0$

$e.$ concave downward when $t>0$