SO₂Cl₂ Decomposes in the Gas Phase by the Reaction SO₂Cl₂

SO₂Cl₂ decomposes in the gas phase by the reaction SO₂Cl₂ (g) → SO₂ (g) + Cl₂ (g)
The reaction is first order in SO₂Cl₂ and the rate constant is 3.0 × 10^-6 s^-1at 600 K. A vessel is charged with 3.6 atm of SO₂Cl₂ at 600 K. The partial pressure of SO₂Cl₂ at 3.0 × 10⁵ s is ________ atm.

A) 0.85
B) 3.2
C) 1.5
D) 0.19
E) 9.3 × 10⁴