4. The movement of magma within a dormant volcano is often ________; while geologists can monitor subtle pressure shifts, the exact timing of a potential eruption remains a matter of probability rather than deterministic certainty.
(A) stochastic
(B) systematic
(C) linear
(D) predictable

The movement of magma within a dormant volcano is often ________; while geologists can monitor subtle pressure shifts, the exact timing of a potential eruption remains a matter of probability rather than deterministic certainty.
休眠火山內岩漿的移動往往是 ______ 的；儘管地質學家可以監測細微的壓力變化，但噴發的確切時間仍屬於機率問題，而非確定性的預測

(A) stochastic 隨機的、機率性的
符合「probability 而非 deterministic」

(B) systematic 有系統的
不符合不確定性

(C) linear 線性的
與語意無關

(D) predictable 可預測的
與「無法確定」相反

整體解析
關鍵線索：
probability（機率）＋ not deterministic（非確定）
代表具有隨機性、不完全可預測

答案：(A) stochastic