Subject Verb Agreement

[abysinha]

Hi

I need help with this conceptual question regarding subject verb agreement and the use of 'and'

"And" will general make two singular pronouns or nouns as plural. (Gold and Silver are precious metals)

However, i was looking through Wren and Martin High School Grammar book and i found this

"but if both the nouns suggest one idea to the mind, or refer to the same person or thing, the verb used will be singular"
e.g.
The horse and carriage is at the door
Bread and butter is his only food
Honor and Glory is his reward
the rise and fall of the tide is due to lunar influence "


I am thoroughly confused now

What should be the best answer here

In him were centered their love and their ambition
In him was centered their love and ambition

Thanks for your help
Aby