When developing a real estate project, it is usually true that a. it is more expensive to preserve existing walls then to build new ones b. when doing any construction, it is always better to use Union workers c. construction sites are, by law, kept very safe and accident-free d. it is always necessary to hire an Owner's Rep to watch over the site and frequently report back to the owners e. for small real estate development, large scale construction equipment, such as cranes, are unnecessary