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In the conversion of alkyne to trans-alk...

In the conversion of alkyne to trans-alkene by Birch reduction using alkali metals (such as `Na` or `K`) in liquid `NH_3` and alcohol (`MeOH` or `EtOH`),
`R - -= - R overset(Na +liq. NH_(3))underset(+EtOH)rarr`
the mechanism takes place in the formation of intermediate species in the following sequence:

A

(a) Radical anion `rarr` vinylic radical `rarr` trans-vinylic anion `rarr` trans-alkene

B

(b) Radical anion `rarr` trans-vinylic anion `rarr` vinylic radical `rarr` trans-alkene

C

(c) Vinylic radial `rarr` radical anion `rarr` trans-vinylic anion `rarr` trans-alkene

D

(d) Vinylic radical `rarr` trans-vinylic anion `rarr` radical anion `rarr` trans-alkene

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The correct Answer is:
A
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