Answer:
By accepting a false null hypothesis he committed a type II error.
Explanation:
Type II error is to accept H0 when H0 is false.
If there's a type II error then the null hypothesis is false ie the adoption rate is less than 15 %, when the true adoption rate is not less than 15% . He has accepted the null hypothesis as true and taken the wrong decision of not accepting any new animals into the shelters that week.