The question asks you to classify a sequence related to stock prices, as seen from the options and text. Let's carefully interpret the content.

From the problem:

1. The share price drops as follows:
   • Initial price: $27.50
   • After 2nd hour: $27.25
   • After 4th hour: $27.00
   • It keeps dropping by the same pattern ($0.25 per interval).

Identifying the sequence type:

• Arithmetic sequences have a common difference (each term changes by adding or subtracting a fixed number).
• Geometric sequences have a common ratio (each term changes by multiplying by a fixed number).

Here:

• The sequence decreases by a constant difference of -0.25 each time (27.50 → 27.25 → 27.00).
  Thus, this is an arithmetic sequence.

Correct Completion:

1. Part A: "have a common difference."
2. Part B: "arithmetic."

Would you like more details about arithmetic sequences or have further questions?

Five Related Questions:

1. How do you differentiate between arithmetic and geometric sequences?
2. How can you find the common difference of an arithmetic sequence?
3. What formula determines the $n$-th term in an arithmetic sequence?
4. How do arithmetic sequences appear in real-world financial problems?
5. Can an arithmetic sequence ever increase? If so, how?

Tip: In an arithmetic sequence, if the common difference is negative, the sequence decreases steadily.