Identify the sources of Human Capital Formation and choose the correct alternative to fill in the blanks.

Human Capital Formation refers to the development of skills, knowledge, and health to increase productivity. Key sources include:
Expenditure on Health: Ensures a healthy workforce capable of higher productivity.
Expenditure on Migration: Allows skilled labor to move to regions with better opportunities, enhancing productivity.
Draw a rough sketch for the curve $y = 2 + |x + 1|$. Using integration, find the area of the region bounded by the curve $y = 2 + |x + 1|$, $x = -4$, $x = 3$, and $y = 0$.
Study the given molecular structure of double-stranded polynucleotide chain of DNA and answer the questions that follow. 
(a) How many phosphodiester bonds are present in the given double-stranded polynucleotide chain?
(b) How many base pairs are there in each helical turn of double helix structure of DNA? Also write the distance between a base pair in a helix.
(c) In addition to H-bonds, what confers additional stability to the helical structure of DNA?
