Step 1: Test I $$ II (I as cause).
Domestic fuel prices staying unchanged} cannot cause} international crude prices to rise. Global crude prices are driven by worldwide supply–demand/geopolitics, not by one country’s retail price level. $$ (A) is untenable.
Step 2: Test II $$ I (II as cause).
If international crude rises substantially}, the natural effect is an increase} in domestic fuel prices, not “unchanged”. The observed stability is more plausibly due to government price control/subsidy/hedging. Hence II does not} cause I directly. $$ (B) fails.
Step 3: Decide between (C) and (D).
- Statement II (global crude up) is an effect} of its own independent causes (OPEC decisions, wars, demand spikes, etc.).
- Statement I (domestic prices unchanged) is also an effect} of a different independent cause (policy decision, subsidy cushion, price freeze).
Thus both are effects} of different causes, not causes themselves. $$ (D).
\[
\boxed{\text{(D) Both I and II are effects of independent causes}}
\]