Both the the options `(b)` and `(c)` are ` 3 ^(@)` alcohols, but in `(c)`, `3^(@)` carbocation is more stable due to resonance and gives a more substituted alkens .
`b.`
c.
Similarly, both (a) and (d) are `2^(@)` alcohols, but in (d), `2^(@)` carbocation can be stabilised to `3^(@) C^(o+)` via `1,2-H^(o-)` shift and gives more substituted alkene.
4.
So, the ease of dehydration is `:`
`(c) gt (b) gt (d) gt (a) gt (e)`
