Final answer:
The sentence 'In reaction to rising oil prices, auto manufacturers developed hybrid cars' is in past tense, indicated by the verb 'developed'.
Step-by-step explanation:
The sentence 'In reaction to rising oil prices, auto manufacturers developed hybrid cars' uses Past tense. The verb 'developed' indicates that the action has already been done.
In this context, auto manufacturers already responded in the past to the rising oil prices by developing hybrid cars. This isn't something they plan to do in the future (future tense), or are doing right now (present tense), nor is it an action started in the past and continues to the present (present perfect tense).
Examples of other verb tenses would be: 'Auto manufacturers will develop hybrid cars' (future tense); 'Auto manufacturers are developing hybrid cars' (present tense); 'Auto manufacturers have developed hybrid cars' (present perfect tense).
Learn more about Verb Tenses