Which of the following halides will be most reactive in SN2 reaction and SN1 reaction, respectively?
(I), (II)
(II), (I)
(I), (IIl)
(III), (I)
(I) ⇒1∘ allylic halide and less steric hindrance, hence SN2
(III)⇒3∘allylic halide, most stable carbonium ion and SN1