Select the INCORRECTLY spelt

Consider the following pseudo-code: 

 ```

    function calculate(arr):

        sum = 0

Which deadlock prevention scheme allows older transactions to preempt younger ones?

Which interrupt is generated by software?

Which type of join returns only matching records from both tables?

Shadow Paging avoids:

In the context of computer networks, what is the primary function of a router?

Bitmap indexes are most efficient when:

What does re.sub(r'(\w+)', r'_\1_', 'hello world') return?

Which of the following is NOT a common type of error encountered during software development? 

In a relational database, what is a foreign key?