Three statements are followed by three conclusions numbered I, II and III. You have to consider these statements to be true, even if they seem to be at variance with commonly known facts. Decide which of the given conclusions logically follow(s) from the given statements.
Statements:
(1) All potatoes are tomatoes.
(2) All tomatoes are brinjals.
(3) All brinjals are onions.
Conclusions:
(I) Some onions are potatoes
(II) All tomatoes are potatoes
(III) No tomato is a potato​​

​Statements:
(1) All potatoes are tomatoes.
(2) All tomatoes are brinjals.
(3) All brinjals are onions.

Conclusions:(I) Some onions are potatoes:

This is true because all potatoes are onions (as derived from the statements). If all potatoes are onions, then naturally, "some onions are potatoes."

Conclusions:(II) All tomatoes are potatoes:

This is false because the statement says all potatoes are tomatoes, not the other way around. Not all tomatoes are potatoes.

Conclusions:(III) No tomato is a potato:

This is false because we know that all potatoes are tomatoes, so there is some overlap between tomatoes and potatoes. This makes "no tomato is a potato" incorrect.

Thus, the correct option is (d) Only conclusion I follows