Is the correct answer a ?

it foreshadows the theme of the paragraph and hints the topic that will be discussed in the paragraph!

i think that it would be tenth of the first

small european communities with shared traditions consolidated into large new states (apex)

the outcome of 1970 oil crisis in united states was that, they began to search ways on how to reduce oil.

in 1970 was a period when there were energy and oil crisis. those who were major centers for industrialization were forced to keep way from supplying of petroleum.

some of the result of this crisis was economic growth became stagnant because prices of oil surged.

due to the increased prices some countries like mexico and norway benefited.