The rate of the reaction (CH3)3CCl + NaSCH2CH3 - (CH3)2C==CH2 + CH3CH2SH + NaCl is first-order in

Question:

The rate of the reaction
(CH3)3CCl + NaSCH2CH3 -→ (CH3)2C==CH2 + CH3CH2SH + NaCl
is first-order in (CH3)3CCl and first-order in NaSCH2CH3. Give the symbol (E1 or E2) for the most reasonable mechanism, and use curved arrow notation to represent the flow of electrons.