To evaluate the reliability of the statements, we should analyze the content of each one:
A. "The first pioneers to explore the opal fields found an unpleasant and unfriendly environment." - This is a general statement that can be considered reliable as it reflects the challenges faced by early pioneers in harsh environments.
B. "None of the pioneers liked summer because it was dreadfully hot." - This statement seems to express a subjective opinion. While it can be true that many pioneers might have disliked the extreme heat, saying "none" is a strong assertion, making it less reliable.
C. "To adapt to the challenging environment, pioneers built underground homes." - This is a factual statement that can be historically accurate, as building underground structures is a common adaptation in harsh climates.
Given this analysis:
- A is reliable.
- B is unreliable due to the extreme wording ("none").
- C is reliable.
Thus, the correct evaluation of reliability is: A is reliable, B is unreliable, C is reliable.