Recently, which of the following States has explored the possibility of constructing an artificial inland port to be connected to sea by a long navigational channel?

1. The question asks about a State exploring the possibility of constructing an artificial inland port connected to the sea by a long navigational channel around 2015-2016. 2. During that period, the state government of Rajasthan initiated discussions and studies regarding the feasibility of developing an inland port near Jalore district. 3. The concept involved creating the port facility inland and connecting it to the Arabian Sea via a long channel, possibly utilizing creek systems in neighboring Gujarat. 4. This proposal aimed to provide landlocked Rajasthan with direct access to maritime trade. 5. Therefore, Rajasthan (Option D) is the state that explored this specific concept around the time the question was framed.