The given sentence is divided into four segments. Select the option that has the segment with a grammatical error.

I am sure / that he will praying / for a good crop / this year.

The correct option containing a grammatical error is "that he will praying".

Explanation:
In English grammar, modal auxiliary verbs like "will" must be followed by the base form of the main verb (infinitive without 'to') when forming the simple future tense, or by "be + verb-ing" to form the future continuous tense.

In the segment "that he will praying", the present participle "praying" directly follows the modal verb "will" without the auxiliary verb "be", which is grammatically incorrect.

To correct the sentence, it should be changed either to:
1. Simple Future Tense: "that he will pray"
2. Future Continuous Tense: "that he will be praying"

Corrected Sentence:
"I am sure that he will pray for a good crop this year." or "I am sure that he will be praying for a good crop this year."