Answer:
B. satisfied and confident
Step-by-step explanation:
In this poem, Whitman describes how different individuals sing while doing their job; the piece has a joyful and appreciative tone and uses words like carol, the delicious singing of the mother, strong melodious songs, which, at the same time, helps un infer the meaning of blithe. The second line, then, states that people working in mechanics sing their carols as it should be: blithe and strong, that is to say, happy, satisfied and confident.