Take context from the input text and decide on the accurate relationship between 'Boston Pizza' and 'restaurant' from the options provided.
Options: headquarters location, developer, product/material produced, parent organization

The decline in same restaurant sales year-to-date was principally due to declines in restaurant guest traffic and the temporary closure of all dining rooms and sports bars in the Boston Pizza restaurants across Canada on March 17, 2020, again both as a result of the COVID pandemic but partially offset by the increased takeout and delivery sales that I mentioned a moment ago.
product/material produced