Think of the perinatal window as a bridge that starts in late pregnancy and ends one week after birth. It begins at 28 weeks of gestation and closes at the end of the seventh day of life. Because it straddles birth, it has to pull in events from both sides of delivery: babies who die in the womb late in pregnancy and are born dead (still births) and babies who are born alive but die in the first week.
So the correct numerator is still births added to early neonatal deaths, and the whole thing is reported per 1,000 total births.
Screening the options against this picture: pairing still borns with deaths in the first 7 days fits perfectly. Counting neonatal deaths up to 30 days stretches into the neonatal mortality definition instead. Pulling in abortions is wrong because they occur before the 28 week boundary. Counting only deaths from day 7 to day 28 describes the late neonatal slice, not the perinatal one.
\[\boxed{\text{Still borns and deaths within 7 days of birth}}\]