At time $t=0,$ a bullet is fired vertically upwards with a speed of $98\frac{m}{s}.$ At time $t=5$ seconds a second bullet is fired vertically upwards with the same speed. If the air resistance is neglected. Which of the following is correct?

a$.$ the two bullets will be at the same height above the ground at $t=12\mathrm{.}5sec$

b$.$ the two bullets will reach back their starting points at the same point

c$.$ the two bullets will have the same speed at $t=20s$

d$.$ the two bullets will attain the same maximum height