Step 1: Method:
We pair each term with its meaning by first picking the pairs we are sure about, and then using those pairs to rule out the options one by one.
Step 2: Pair the sure ones:
Prejudice is about attitudes and opinions formed in advance, so it pairs with III. Stratification is about the ranking of groups in a society, so it pairs with IV.
Step 3: Rule out options:
Option 1 has A with I, which does not fit the first sure pair. Option 2 has B with I, which does not fit the second sure pair. Option 3 has A with IV, which also breaks the first pair. Only option 4 keeps A-III and B-IV.
Step 4: Confirm the rest:
In option 4 the last two pairs are C-I and D-II. Exclusion means being cut off from full part in society, which is I. Discrimination means shutting a group out of opportunities others have, which is II. Both pairs fit well.
Step 5: Why the other pairings fail:
Pairing prejudice with exclusion would mix up an attitude with a condition of being cut off. Pairing stratification with the idea of disqualifying people mixes up a ranked order with an action. Keeping attitudes, ranking, cut-off condition and unequal treatment apart is the safest way to avoid these traps.
Final Answer:
The full matching is A-III, B-IV, C-I, D-II. \[\boxed{4}\]