Income tax capital gain in partnership firm

In a partnership firm having A & B partners , one of the  partner "A" is retired .the firm will be converted to propritorship having prop "B". "A' will gate the full amount of capital as on date.and 'B' will take over full assets of the firm and continues the buisness.

then what is position of "A" and "B" ,will they attract any CAPITAL GAIN?

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