Question

What is most likely the author’s motive for writing the article?

to get the reader to buy digital products
to get the reader to support the conversion from analog to digital
to get the reader to raise money for digital research
to get the reader to understand the two types of signals

Answer 1

To get the reader to understand the two types of signals — the article is explanatory, comparing and describing analog and digital signals rather than persuading or fundraising.