This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
Which is derived from thoracolumbar fascia - 
Select and explain. 
A. Medial arcuate ligament, B. Lateral arcuate ligament, C. Lacunar ligament, D. Cruciate ligament
B: Lateral arcuate ligament
Answer: B: Lateral arcuate ligament 
Explanation: Ans. is 'b' i.e., Lateral arcuate ligament o Thoracolumbar fascia covers the deep muscles of back of the trunk, o It is composed of three fascial layers -i) Anterior layer# It is the thinnest layer# Medially it is attached to transverse process of lumbar vertebrae.# Laterally it fuses with fascia transversalis and aponeurosis of transversus abdominis# Inferiorly it is attached to iliolumbar ligament and iliac crest.# Superiorly it is attached to 12th rib and extends to transverse process of Lj forming the lateral arcuate ligament of diaphragm.ii) Middle layer# Medially it is attached to transverse process of lumbar vertebrae.# Inferiorly it is attached to iliac rest.# Superiorly it is attached to 12th ribiii) Posterior layer# It is the thickest layer and attached to spines of lumbar verterae.o Quadratus lomborum is enclosed between anterior and middle layers. Erector spinae (paraspinal muscle) is enclosed between middle and posterior layer.