After this year’s record-shattering January performance in Madison Square Garden, the ensemble were touted as the country’s best new group in decades; no critic or reviewer had anything but praise for the young musicians.

(A) the ensemble were touted as the country’s

(B) the ensemble was touted as the country’s

(C) the country touted the ensemble like the

(D) touting the ensemble as the country’s（B）

(E) they were touting the ensemble as the country’s

不太清楚，ensemble后面什么情况下用单数，什么情况下用复数。

longman里这么说的：

1
[countable also + plural verb] British English a small group of musicians, actors, or dancers who perform together regularly
instrumental/string/brass etc ensemble
ensemble of
an ensemble of Mexican artistes
2
[countable usually singular] a set of things that go together to form a whole
3
[countable usually singular] a set of clothes that are worn together
an attractive ensemble

看来看去觉得1和2差不多

1
[countable also + plural verb] British English a small group

of musicians, actors, or dancers who perform together

regularly
instrumental/string/brass etc ensemble
ensemble of
an ensemble of Mexican artistes

可这里面说到后面可以接复数。。