The answer, unfortunately, depends on which reading you cite.
I presume that this comes from the currency management reading; if so, then it should be (3).
However, this is not the customary definition of roll yield, which is correctly defined in one of the Level III commodities readings.
There is a commodities reading at Level I and a commodities reading at Level II each of which has an incorrect (i.e., not the customary definition) of roll yield, which are different from each other, and neither of which agrees with the (equally incorrect) definition from the Level III currency management reading.