During cellular respiration, pyruvic acid is converted into lactic acid when oxygen is present in the cell.

A. skeletal MT:Skeletal muscle tissue is striated and voluntary, with long multinucleated fibers. The nuclei are located at the periphery of the cells, making it different from the muscle type described.

B. cardiac MT:Cardiac muscle tissue is striated and involuntary, with cells that usually contain one centrally located nucleus. It also features intercalated discs that allow synchronized contraction, matching the characteristics given.

C. smooth MT:Smooth muscle tissue is involuntary but non-striated. The cells are spindle-shaped with a single central nucleus, so it does not meet the description that includes striations.

D. All types of muscle tissue have these characteristics:Not all muscle types share striations, involuntary control, and a single central nucleus. This description specifically fits cardiac muscle tissue rather than all types.

A. adipose CT:Adipose tissue primarily stores fat for energy and cushioning and does not provide the elasticity or vibration properties required for vocal cords.

B. elastic CT:Elastic connective tissue contains abundant elastic fibers, allowing the vocal cords to stretch and recoil during sound production. Its flexibility and resilience are essential for the rapid vibrations needed for speech.

C. areolar CT:Areolar tissue is a loose connective tissue that provides support and cushioning but lacks the dense elastic fibers necessary for vocal cord function.

D. elastic cartilage CT:Elastic cartilage provides flexible support in structures like the ear and epiglottis but is not the main tissue responsible for the vibration and elasticity of vocal cords.