Under the pact concluded by the washington naval conference of 1921, japan was allowed to build ship(s) for every five ships built by britain and the united states each.
a, 3
b, 4
c, 6
d, 2

According the history the number of ships was 3. The answer is option A.

Explanation:

The WNC ( Washington Naval Conference) was an international conference did call by the United States celebrated between 1921-1922.

The meeting had  an object  very important that was to limit the naval arms race at the pacific area.

The countries involved were United States, Great Britain, Japan and France.

Japan is considered as one f the three crucial primary powers involved in the regime. One of the agreement of this conference was to limite Japan to build ships in 3 units by every five ships built by Britain and US.

c

explanation: