I am going to take D here... here is why:
Premise: Winter -> price of oil low now, likely to remain so
....missing premise, must be something about nat. gas....
Conclusion: Price of natural gas -> to stay low, UNLESS "real" winter strikes.
Which of the following, if true, provides the
most support for the conclusion above?
What type of question is this?... no... not conclusion...
this is strengthen question... we need to find a support for conclusion that price of natural gas will stay low. Now... since there is no premise (info) about natural gas, the answer should say something about it to draw such conclusion.
(A) OUT OF SCOPE... no indication of that... in fact, the argument is uncertain about the weather.
(B) OUT OF SCOPE... do we care about the fact that they can switch from 1 to 2? how does it support the conclusion that price on natural gas will stay low? THIS ONE IS A TRAP!!!
(C) OUT OF SCOPE... we don't know anything about where the oil/gas comes from
(D) The fuel requirements of industrial users of natural gas are not seriously affected by the weather.
By POE this is the one; Let's negate this one and see what happens:
The fuel requirements of users of nat. gas ARE seriously affected by the weather. Thus, the prices of gas WILL NOT stay lower... AHA -> conclusion FALLS APART... so this is correct choice
(E) Opposite is true... in fact, both oil and gas seem to be affected together