The correct answer is (B) Lack of flavour, dullness without distinctive, interesting or attractive qualities; without adequate taste. Also, an insipid remark, or the condition or state of being insipid.

Insipidity comes from Latin insipidus.

Examples of use:

• His lecture was a study in insipidity enlivened only by the ending bell.
• Her insipidity was unchanging for her spirit was always the same.