1.    A channel of distribution

    a)    is only needed when products must be stored.
Oh yeah, right, like travel agents (selling intangibles) are not part of a channel of distribution!
    b)    must include one or more middlemen.
Not true, a direct channel, which doesn't include middlemen, is also a channel of distribution.
    c)    is any series of firms or individuals who participate in the flow of goods and services from  producer to consumer or final user.
Yes! Right answer.
    d)    helps create possession utility but not time utility.
On the contrary, channels provide time utility galore.
    e)    both a) and c).
Obviously not.