Directions: The question is a logical sequence of statements with a missing link, the location of which is shown parenthetically. Choose the alternative that best fits the sequence logically.

This great increase of the quantity of work which, in consequence of the division of labour, the same number of people are capable of performing, is owing to three different circumstances; first, to the increase of dexterity in every particular workman; secondly, to the saving of the time which is commonly lost in passing from one species of work to another; and lastly, to the (..) which facilitate and abridge labour.