Answer:
B. past
Step-by-step explanation:
-Past perfect tense indicates that an action occurred before something else and it is formed by using had + past participle of the verb.
-Past tense indicates that an action happened before now and in the case of regular verbs it is formed by adding -ed at the end of the verb.
-Future tense refers to something that will happen later and it is formed by using a modal+infinitive of the verb.
-Future perfect refers to an action that will be finished in the future and it is formed by using will have + past participle of the verb.
According to this, the answer is that the suffix -ed in the italicized word in the sentence above illustrates that the work happened in the past tense.