We start with the given fact: Grumbs is a Bingo.
From the rules: If Grumbs is used, Ihavitoo must also be used in the sentence — and vice versa.
However, Ihavitoo can be used as either a Bingo or a Cingo, because it belongs to both categories.
Since a sentence must have exactly 2 Bingoes, and Grumbs already occupies 1 Bingo slot, Ihavitoo does not necessarily have to be the other Bingo — it could be placed in the Cingo slot.
Therefore, the statement “Ihavitoo must be a Bingo” is not necessarily true, making it the one that cannot be true under all circumstances.
Checking each option:
(A) Harrumphs must be a Bingo — This can be true if Ihavitoo is used as the Cingo, leaving Harrumphs to fill the 2nd Bingo slot. It’s possible, so not the “cannot” case.
(B) Ihavitoo must be a Bingo — This is false because Ihavitoo can be the Cingo instead. Thus, this is the “cannot” case.
(C) Lovitoo may be used — This is possible; Lovitoo is a Dingo and there is no restriction against it here.
(D) All three Bingoes are used — Impossible under the rule “exactly 2 Bingoes,” but here the statement “cannot be true” applies to (B) more strictly because (D) violates the basic grammar structure, not the given scenario logic. The question asks in the context of Grumbs as Bingo without breaking rules, and (D) would break rules immediately. However, the focus is on the necessity claim in (B).
Given the wording, the most precise choice for “cannot be true” in the sense of not being logically necessary is (B).
\(\boxed{\text{Correct Answer: (B)}}\)