The following U$.$S$.$ crude oil storage chart could represent:

a$.$ NYMEX prices are expected to have a strong bullish outlook

b$.$ Recent global crude oil demand is the highest in the past $5$ vears

c$.$ Refined product demand is strong

d$.$ None of the above

Given that the chart $($below$)$ represents the history of the differences between Transco Zone $6$ NY natural gas prices and the NYMEX Henry Hub $(HH)$ natural gas prices $($TZ$6-HH),$ which of the following statements would be a reasonable explanation for the pfice differences above:

a$.$ Pipeline capacity between locations may be constrained during winter periods

b$.$ Traders use Intemuptible Transportation contracts to capture price spikes

c$.$ The BTU content of the natural gas varies between locations

d$.$ None of the above