Proof of a generalization of the (C.2) supercongruence of Van Hamme

We prove some q-supercongruences for certain truncated basic hypergeometric series by making use of Andrews' multiseries generalization of the Watson transformation, the creative microscoping method, and the Chinese remainder theorem for coprime polynomials. More precisely, we confirm Conjectures 5.2 and 5.3 in Guo (Adv Appl Math 116:Art. 102016, 2020). As a conclusion, we also prove Conjecture 4.3 in Guo (Integral Transforms Spec Funct 28:888-899, 2017) which may be deemed a generalization of the (C.2) supercongruence of Van Hamme.