Recently, linking of which of the following rivers was undertaken?

1. The question asks about the linking of rivers that was undertaken around 2016. 2. In September 2015, the linking of the Godavari and Krishna rivers was formally commissioned in Andhra Pradesh through the Pattiseema lift irrigation project. 3. This project involves lifting water from the Godavari River and diverting it into the Polavaram Project's Right Main Canal, which connects to the Prakasam Barrage on the Krishna River. 4. This represents a major inter-basin water transfer project, effectively linking the two large peninsular rivers. 5. The other pairs listed (Cauvery-Tungabhadra, Mahanadi-Sone, Narmada-Tapti) were part of broader inter-linking proposals but the Godavari-Krishna link via Pattiseema was a project that was actively undertaken and commissioned in the period relevant to the question.