:(

Designed to encourage debate, the long-standing "equal-time" rule for broadcasters has, some contend, actually stifled it.

(A) the long-standing "equal-time" rule for broadcasters has, some contend, actually stifled it.
>> seems ok to me.
(B) some contend that the long-standing "equal-time" rule for broadcasters has actually stifled it
>>here instead of "it", "itself" should be used. Because subject is rule for broadcaster.
(C) it has actually been stifled, some contend, by the long-standing
"equal-time" rule for broadcasters

>>wrong S-V agreement.
(D) some contend that it has actually been stifled by the long-standing "equal-time" rule for broadcasters

>>wrong S-V agreement.
(E) actually, the long-standing "equal-time" rule for broadcasters has stifled it, some contend

not sure why is this option wrong, but it looks very awkward in its structure.

so option A

sana.noor wrote:Designed to encourage debate, the long-standing "equal-time" rule for broadcasters has, some contend, actually stifled it.

(A) the long-standing "equal-time" rule for broadcasters has, some contend, actually stifled it.
(B) some contend that the long-standing "equal-time" rule for broadcasters has actually stifled it
(C) it has actually been stifled, some contend, by the long-standing
"equal-time" rule for broadcasters
(D) some contend that it has actually been stifled by the long-standing "equal-time" rule for broadcasters
(E) actually, the long-standing "equal-time" rule for broadcasters has stifled it, some contend

the answer is A

DESIGNED TO ENCOURAGE DEBATE should modify RULE(not SOME or IT). Drop B/C/D

E- do not know what ACTUALLY modify (DESIGNED or STIFLED). The intent is to modify verb HAS STIFLED.
'ACTUALLY DESIGNED to encourage debate' OR "BROADCASTERS HAS ACTUALLY STIFLED IT" - emphasise is on the STIFLED.

IMO A