Strategic Arms Reduction Treaty (START-1) was signed by USSR President Mikhail Gorbachev and US President George Bush (Senior) in:

Moscow

The correct answer is Option 3 - Moscow

STRATEGIC ARMS REDUCTION TREATY I (START-I): Treaty signed by the USSR President Mikhail Gorbachev and US President George Bush (Senior) on the reduction and limitation of strategic offensive arms in Moscow on 31 July 1991.

STRATEGIC ARMS REDUCTION TREATY II (START-II): Treaty signed by the Russian President Boris Yeltsin and the US President George Bush (Senior) on the reduction and limitation of strategic offensive arms in Moscow on 3 January 1993.