In the following questions, few sentences are given. Choose and mark the sentence which contains no grammatical or contextual error in it. If all the sentences are grammatically and contextually incorrect, mark "All are incorrect" option as the answer choice.

To find the grammatically and contextually correct sentence, let us analyze each option step-by-step:

1. "The number of unemployed graduates have risen sharply over the past two years."
Error: Subject-verb agreement.
The subject phrase starting with "The number of..." is singular and takes a singular verb. Therefore, "have risen" should be replaced with "has risen". (Note: "A number of..." takes a plural verb, but "The number of..." takes a singular verb.)

2. "She is one of those leaders who inspires everyone around them."
Error: Subject-verb agreement in the relative clause.
In the structure "one of those + plural noun + who/that", the relative pronoun "who" refers back to the plural noun "leaders". Therefore, the verb that follows must be plural. "Inspires" (singular) should be replaced with "inspire" (plural).

3. "The report, along with its appendices, were submitted to the board."
Error: Subject-verb agreement.
When a subject is connected with other nouns/pronouns using parenthetical expressions like "along with", "as well as", "together with", or "in addition to", the verb agrees with the first subject. Here, the main subject is "The report" (singular), so the verb should be "was submitted" instead of "were submitted".

4. "Despite of working overtime, he could not complete the project on time."
Error: Preposition redundancy.
The word "despite" is a preposition and should not be followed by "of". We either use "Despite working..." or "In spite of working...". Therefore, "Despite of" is grammatically incorrect.

5. "The Reserve Bank of India has raised the repo rate to curb inflationary pressures."
Correct: This sentence is grammatically and contextually correct. "The Reserve Bank of India" is a singular subject, which correctly takes the singular verb "has raised". The infinitive phrase "to curb inflationary pressures" is used correctly to show purpose.

Therefore, the only grammatically and contextually correct sentence is: "The Reserve Bank of India has raised the repo rate to curb inflationary pressures."