An encyclopedia is an example of a select one: a. online database b. reference work c. journal d. periodical

B). Reference work.

Explanation:

Reference works are described as a periodical work or book that are primarily intended to provide factual information to the readers and to which they can refer for established/confirmed information or facts. Such works are not meant to be read from the introduction or beginning to the end but rather a compendium intended to make it convenient for reference either in pieces for varied purposes or as a whole.

As per the question, 'encyclopedia' exemplifies a 'reference work' as it is used a compendium to which people refer for information and for ensuring/confirming facts. It(encyclopedia) offers a vast range of subjects and domains along with their varied aspects that propose a flood of information out of which the readers could refer to as per their interests and subjects. Thus, option B is the correct answer.

the service industry in the united states grew in the late 1800s. what was one effect of that growth?

the number of people with jobs in factories as unskilled workers decreased.

the number of people with jobs in factories as unskilled workers increased.

the middle class grew as people took jobs as clerks, lawyers, and teachers.

the middle class shrank as people left jobs as clerks, lawyers, and teachers.