What Is 21+21,000 Please tell me what the answer

Use the graph of the sine function y=2sinθ shown below

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days

What is the common difference for this arithmetic sequence? -6,-2,2,6,10 a.4 b.5 c.3 d.6