Polysaccharides with both 1,4 and 1,6 glycosidic bonds are branched.

Steps:

• Linear polysaccharides form straight chains using only 1,4 glycosidic bonds.
• Branched polysaccharides require 1,4 bonds for linear segments and 1,6 bonds at branch points.
• Examine the given polysaccharides: numbers 1 and 4 are branched structures.
• Confirm they contain both bond types, while others do not.

Why B is correct:

• Polysaccharides 1 and 4 are branched, defined by α-1,4 linkages in chains and α-1,6 linkages at branches.

Why the others are wrong:

• A: Polysaccharide 3 uses only 1,4 bonds in a linear structure.
• C: Polysaccharide 2 relies solely on 1,4 bonds without branching.
• D: Polysaccharide 1 also contains both bonds, not just 4.

Final answer: B