Which trade route did Arab pirates threaten, prompting increased Royal Navy operations?

The correct choice pertains to the Red Sea to Bombay trade route, as it was significantly impacted by the activities of Arab pirates. During the late 18th and early 19th centuries, this region saw a rise in piracy, which raised concerns among maritime powers. The trade route was crucial as it connected the Indian subcontinent with the Middle East and Europe, making it vital for trade in spices, textiles, and other valuable commodities.

The threat posed by piracy led the British Royal Navy to increase its maritime patrols in these waters to protect merchant vessels and ensure the safe passage of goods. This heightened military presence was a direct response to safeguarding trade interests and preventing economic disruption. In contrast, the other routes mentioned either did not see the same levels of piracy or were not as crucial to British maritime trade during that period, which accounts for their exclusion as the correct answer. By focusing efforts on the Red Sea to Bombay route, the Royal Navy aimed to maintain the stability of international trade and assert control over strategic maritime passages.