Which of the following is considered a qualitative factor in financial analysis?

a$.$ A company's current ratio increased from $1\mathrm{.}5$ to $2\mathrm{.}0$ over the past fiscal year.

b$.$ A company's stock price has declined over the past year.

c$.$ A company has several promising products in the research and development phase.

d$.$ A company's trend analysis shows a consistent increase in the cost of goods sold over the past five years.