The BRICS Foreign Ministers' Meeting on 4 June 2018 took place in which city?

The correct option is Pretoria, South Africa.

Explanation:

The BRICS (Brazil, Russia, India, China, and South Africa) Foreign Ministers' Meeting took place on June 4, 2018, in Pretoria, South Africa.
This formal meeting was chaired by South Africa's then Minister of International Relations and Cooperation, Lindiwe Sisulu, as South Africa held the BRICS Chairmanship for the year 2018.
The meeting served as a key preparatory session for the 10th annual BRICS Summit, which was subsequently hosted in Johannesburg in July 2018.