Concept:
Nādanusandhāna is an important meditative practice described in the Hatha Yoga Pradipika. It involves concentration on the inner mystical sound (Nāda) heard during deep meditation.
This practice is associated with attaining mental absorption and ultimately Samadhi. The Hatha Yoga Pradipika explains that the practitioner experiences different stages of inner sound perception during spiritual progress.
Step 1: Understand the meaning of Nādanusandhāna.
The term:
\[
\text{Nāda} = \text{Inner mystical sound}
\]
and
\[
\text{Anusandhāna} = \text{Continuous meditation or investigation}
\]
Thus, Nādanusandhāna means meditation on the inner sound current.
Step 2: Identify the stages of Nādanusandhāna.
According to the Hatha Yoga Pradipika, Nādanusandhāna consists of four stages:
• Ārambha Avasthā
• Ghata Avasthā
• Parichaya Avasthā
• Nishpatti Avasthā
Therefore:
\[
\text{Number of stages} = 4
\]
Step 3: Analyze the given options.
Option (A): Two
Incorrect. The text mentions more than two stages.
Option (B): Three
Incorrect. Nādanusandhāna is not divided into three stages.
Option (C): Four
Correct. The Hatha Yoga Pradipika describes four stages.
Option (D): Five
Incorrect. The stages are not five in number.
Step 4: Identify the correct option.
Since Nādanusandhāna has four stages according to the Hatha Yoga Pradipika, the correct answer is:
\[
\boxed{\text{Four}}
\]