At what temperature will the rms speed of oxygen molecules becomes just sufficient to escape from the earth's atmosphere?(Given: Mass of oxygen molecule (m) = 2.76 × 10⁻²³ kg , Boltzmann constant i.e. kB = 1.38 × 10⁻²³ JK⁻¹)
A 5 . 016 × 10⁴ K
B 2 . 508 × 10⁴ K
C 1 . 254 × 10⁴ K
D 8 . 360 × 10⁴ K