Concept:
According to Samay-Siddhant, ragas are sung at particular times of the day.
Sandhi Prakash ragas are sung around the transition periods of day and night, especially morning and evening twilight.
Step 1: Understand Sandhi Prakash.
Sandhi means junction and Prakash means light.
So, Sandhi Prakash refers to the time of transition between darkness and light or light and darkness.
Step 2: Understand Re-Dha Komal Varga.
The ragas of this category generally use:
\[
\text{Komal Re}
\]
and
\[
\text{Komal Dha}
\]
Step 3: Identify the related thaat groups.
The thaat groups connected with Sandhi Prakash Varga are:
\[
\text{Bhairava, Purvi, Marva}
\]
Step 4: Final conclusion.
Therefore, the correct answer is:
\[
\boxed{\text{Bhairava, Purvi, Marva}}
\]
Hence:
\[
\boxed{\text{(A)}}
\]