The correct answer is: A. Older than Parasnath mountain series
The Someshwar series is a group of sedimentary rocks that are found in the Indian state of Bihar. The rocks in the Someshwar series are thought to have been deposited during the Precambrian period, which was about 4 billion to 540 million years ago. The Parasnath mountain series is another group of sedimentary rocks that are found in Bihar. The rocks in the Parasnath mountain series are thought to have been deposited during the Cambrian period, which was about 540 to 485 million years ago. Therefore, the Someshwar series is older than the Parasnath mountain series.
The Rajmahal mountain series is a group of volcanic rocks that are found in the Indian states of Jharkhand and Bihar. The rocks in the Rajmahal mountain series are thought to have been erupted during the Permian period, which was about 299 to 252 million years ago. The Kharagpur mountain series is another group of volcanic rocks that are found in the Indian states of West Bengal and Jharkhand. The rocks in the Kharagpur mountain series are thought to have been erupted during the Triassic period, which was about 252 to 201 million years ago. Therefore, the Someshwar series is older than the Rajmahal mountain series and the Kharagpur mountain series.