Let All Prices Increase at an Annual Rate of 10

Let all prices increase at an annual rate of 10 percent. Suppose, however, that it takes each firm six months to find out that any price but its own has changed. Lucas would expect firms in this environment, in the short run at least, to produce

A) more than they would if they could observe other price adjustments more promptly.
B) less than they would if they could observe other price adjustments more promptly.
C) just as much as they would if they could observe other price adjustments more promptly.
D) just as much as they would if they could observe other price adjustments more promptly only if monetary policy were unaffected.
E) none of the above.