The subroutine SUBSTRING extracts characters from a given string.

For example, SUBSTRING(2, 4, 'Database') would return 'tab'.

The variable y is assigned a value using the statement:

y ← SUBSTRING(3, 7, spacecraft)

Figure 1 shows four variable assignments:

agency ← 'NASA'
rover ← 'Curiosity'
spacecraft ← 'Perseverance'
destination ← 'Mars'

Using Figure 1, what is the value of y?