To balance the trade-off between speed and distance in ADSL, most ADSL service providers have chosen a T1 level of ADSL, and offer it under the trademarked name of ADSL

Incomplete question. The missing option read;

a. CA*net 3

b. DOCSIS

c. G.Lite

d. OE

e. UCAID

c. G.Lite

Explanation:

Remember, the term ADSL stands for, Asymmetric Digital Subscriber Line (ADSL), a telco-enabled service for digital communication.

Indeed, because of the shortcomings of a normal ADSL connection, ADSL service providers often chose to use G.Lite since it does not require a voice-data splitter to split the voice and data signals coming from a communication line, by so doing they are able to balance the trade-off between speed and distance in ADSL.

b. take periodic breaks and alternate between tasks.  

will increase work efficiency, and avoid health issues.

answer; measurable outcome;