According to Mahavira, the correct option to realize the truth is option 1, which is to endure all kinds of pain to the body. Mahavira, the founder of Jainism, believed that the path to enlightenment and truth required strict asceticism and self-discipline. By enduring physical pain, a person would be able to detach themselves from worldly attachments and desires, ultimately leading to a higher state of consciousness.

Option 2, performing sacrifices and pilgrimages, may be a religious practice in other belief systems, but it is not mentioned as a requirement for realizing truth in Mahavira`s teachings.

Option 3, meditating for fixed periods, is an important practice in Jainism but is not the specific method emphasized by Mahavira for attaining truth.

Option 4, discarding the theory of Karma, is not aligned with Mahavira`s teachings. The concept of Karma is fundamental to Jainism, and understanding its implications and practicing non-attachment to its effects is an integral part of the path to enlightenment.

In summary, enduring all kinds of pain to the body is the path towards realizing truth according to Mahavira`s teachings in Jainism.