Final answer:
The line 'If I profane with my unworthiest hand' from Shakespeare's 'Romeo and Juliet' is correctly completed with 'Then my lips, two blushing pilgrims, ready stand'.
Step-by-step explanation:
The correct completion of the line 'If I profane with my unworthiest hand' from William Shakespeare's Romeo and Juliet is option b) 'Then my lips, two blushing pilgrims, ready stand'. This line is part of a sonnet that Romeo speaks when he first meets Juliet; it is rich with religious metaphor, comparing the touch of hands to a pilgrim's touch of a holy shrine and leading to the notion that such a touch might require penance through a kiss.