Cats' reading

Outdoor cats are active both day and night, although they tend to be slightly more active at night. The timing of cats' activity is quite flexible and varied, which means house cats may be more active in the morning and evening, as a response to greater human activity at these times. Although they spend the majority of their time in the vicinity of their home, housecats can range many hundreds of meters from this central point, and are known to establish territories that vary considerably in size, in one study ranging from 7 to 28 hectares (17–69 acres).

- The author refers to "house cats" (line 3) mainly in order to ..... .

1) illustrate the fact that the timing of cats' activity is quite flexible and varied
2) emphasize the difference in activity time between outdoor cats and house cats.
3) provide evidence in support of the statement that not all cats tend to be more active at night

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