Despite strict enforcement, ease of transport leads thousands, including endangered species, to be smuggled abroad. …………………………………………………………………….. .The detection of a staggering 58,442 smuggled amphibians over five years, demonstrates the persistence of the illegal trade despite increasing enforcement, reveals the recently-conducted study by researchers from Freeland India and Turtle Survival Alliance.
The passage talks about India continuing to be a safe haven for turtle trade although, there has been an attempt to enforce stringent laws. Only option d fits as a logical progression of this idea. The other options talk about pollution and wastewater which do not fit the context. Option c talks about seizures of smuggled turtles but the information comes in later in the passage.