Now is an excellent time to invest in the catering business. A survey conducted by Weddings magazine found that 70 percent of the magazine’s readers want a catered wedding reception. An analysis of the catering industry, however, shows that the current number of caterers can serve only 55 percent of the weddings likely to occur each year.

(A) The average wedding reception involves between 50 and 100 guests.
Irrelevant
(B) Approximately a quarter of all weddings take place without a reception.
Even if 1/4 have catered events, still doesn't weaken the logic
(C) Approximately a quarter of all weddings and their associated receptions are paid for by the couples themselves.
Irrelvant who pays

(D) Only half of all catered wedding receptions include sit-down meals.
Talking about catered events not the feasibility of them

(E) Only half of those who say they want a catered wedding reception actually have one.
Weakens: Ans

Also friends, please pay attention to the scope qualifiers.
70 percent of the magazine’s readers
the magazine readers could be 100 or 1000000000.

And
55 percent of the weddings likely to occur each year
this 55 % of weddings again could be 100 or 10000000
there is very little relation between the 70 % and the 55%. although the latter figure may certainly be higher..

Also the 55% of the weddings are not mentioned to have a catered wedding reception.

I still feel E should be the answer