Fill in the blank with a suitable option:
Ajay said, “I lost my ball in the ground.”
Ajay said that ________ in the ground.
(a)he lost my ball
(b)he lost his ball
(c)he had lost his ball
(d)he had lost my ball

Hint: Read the given sentence and try to understand what it means. Now convey it to a third person in your head. Go through the options and see which of them is the closest to the one which you formed. Make sure that the sentence selected fits the context and is grammatically correct.

Complete answer: In grammar, there are two kinds of speech - Direct and
Indirect.
In direct speech, the sentence is written exactly as the person said it. However, in indirect speech, a third person repeats the sentence that was originally said, so there are many changes in the sentence. From direct to indirect, the tense changes from present to past. When you convert a sentence from direct to indirect speech, the tense changes. So, to change the speech here, we must change it back. So, the phrase ‘I lost my ball’ will be converted into a tense that is different from its own. It cannot stay the same, as that would not clarify the exact meaning of the sentence.

Now we know exactly what we are looking for. Let’s look at the given options:
(a)he lost my ball - This option is incorrect as the sentence is in the simple past tense and it does not fit into the given sentence, and the possessive is wrong. This is not the required answer. So, this is an incorrect option.
(b)he lost his ball - This option is incorrect as the sentence is in the simple past tense and it does not fit into the given sentence. This is not the required answer. So, this is an incorrect option.
(c)he had lost his ball - This option is in the correct tense and fits into the given sentence perfectly. This is the required answer. So, this is the correct option.
(d)he had lost my ball - This option is incorrect as the sentence is in the past perfect tense but it does not fit into the given sentence, and the possessive is wrong. This is not the required answer. So, this is an incorrect option.

Note: Identify the grammatically correct and the most contextually sound option.
There are certain rules to be followed for Converting direct speech to indirect speech in order for it to be grammatically correct.