In the following question, a sentence is given in Direct speech. Choose the option that best expresses the same idea in Indirect or reported speech. She said, "I've been in this school since 1998."

Introduction / Context:
This question examines the rules of changing a present perfect continuous idea in Direct speech into Indirect or reported speech. It is a typical grammar item in competitive exams that checks understanding of tense backshift, pronoun and demonstrative changes, and the correct use of "since" to mark a starting point in time. The sentence describes continuous association with a school from 1998 up to a point in the past.

Given Data / Assumptions:

• Direct speech: She said, "I've been in this school since 1998."
• "I've been" stands for "I have been" which is present perfect continuous or a present perfect idea of continued stay.
• The reporting verb "said" is in the simple past.
• The phrase "this school" refers to the speaker's present location at that time.
• The time expression "since 1998" indicates that the action started in 1998 and has continued over a period.

Concept / Approach:
When the reporting verb is in the past tense, present perfect forms in Direct speech generally change to past perfect forms in Indirect speech. Therefore, "I have been in this school" becomes "she had been in that school". Demonstratives also change according to viewpoint: "this" usually becomes "that". The conjunction "that" is normally inserted between the reporting clause and the reported clause in Indirect speech. The time expression "since 1998" remains unchanged because it is an exact point in time and is still valid from the reporting perspective.

Step-by-Step Solution:

Verification / Alternative check:
Check tense sequence: past reporting verb "said" is followed by "had been", which is the correct past perfect. The pronoun "I" has correctly changed to "she" and "this school" has changed to "that school" to reflect the reporting context. The preposition "since" and the year 1998 remain untouched. The sentence reads naturally and clearly shows that she had a long association with the school up to that past point in time.

Why Other Options Are Wrong:
Option B uses "have been" instead of "had been", which breaks the rule of tense backshift and also keeps "this school", ignoring the change of viewpoint. Option C uses "was in this school since 1998", which mixes the simple past "was" with "since", a structure that is not standard for a continuing action from 1998. Option D uses the ungrammatical phrase "was being in that school", which is incorrect because "be" in this context does not take the continuous passive form with "being" plus location.

Common Pitfalls:
A frequent error is to forget the change from present perfect to past perfect or to ignore the change from "this" to "that". Some learners also write "was in that school since 1998" which does not properly show the continuing nature of the stay. In exam situations, remember to check tense, pronouns, demonstratives, and the natural flow of the sentence all at once.

Final Answer:
The best Indirect speech form is She said that she had been in that school since 1998.