I’m not pretty sure about this answer but in my opinion it’s B
From the given options, the activity which exemplifies gathering data by observation is option D: Measuring how many parts workers assemble in an hour. This is the best answer as it uses senses to observe people in naturally occurring situation — according to the definition of observation as a data collection method.
Answer:

Explanation:
marketing is called consumer to consumer marketing
It is the making of product or administration with the particular limited time procedure being for shoppers to impart that item or administration to others as brand advocates dependent on the estimation of the item.
The most noticeable instances of
incorporate eBay, an online closeout web page, and amazon which is used for costumer service.
Answer:
differential revenue = $7
so correct option is a.$7
Explanation:
given data
Product A costs = $6
contribution margin = $3
Product B costs = $12
contribution margin = $4
to find out
the differential revenue for this decision
solution
we get here the differential revenue for this decision that is express
so first we get here selling price for both product that is
selling price product A = Product A costs + contribution margin
selling price product A = $6 + $3 = $9
and
selling price product B = $12 + $4 = $16
so now we get differential revenue that is
differential revenue = selling price product B - selling price product A
differential revenue = $16 - $9
differential revenue = $7
so correct option is a.$7