Why "ought" is not the right answer here?

English Language Tests, Intermediate level

ESL/EFL Test #100 [color=blue]“Student Teacher Dialogue (3)”, question 3

Teacher: Excellent. Now if I wanted to describe my time in Paris in 1999 with the verb ‘stay’, what I say?

(a) am
(b) would
© ought
(d) have

English Language Tests, Intermediate level

ESL/EFL Test #100 [color=blue]“Student Teacher Dialogue (3)”, answer 3

Teacher: Excellent. Now if I wanted to describe my time in Paris in 1999 with the verb ‘stay’, what would I say?

Correct answer: (b) would

Your answer was: [color=red]incorrect
Teacher: Excellent. Now if I wanted to describe my time in Paris in 1999 with the verb ‘stay’, what ought I say?
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Dear Sir,

why “ought” is not the right answer here?

Thanks in advance

Chrisitna

.
Ought requires the infinitive ‘to’-- What ought I to say?– except in question tags: I ought to say something, oughtn’t I?
.