Which two methods are acceptable for securing or tying tower sections to a structure when erected internally?

The correct choice involves the use of collar and yolk systems for securing or tying tower sections to a structure when erected internally. This method is essential for maintaining stability and integrity during the erection process.

Collars are horizontal stabilizing members that encircle the tower sections, providing a firm connection and distributing loads evenly. Yokes, typically used in conjunction with collars, can provide further support by connecting multiple sections securely to each other or to the building structure itself. This setup helps to ensure that the tower’s weight and any lateral forces are properly managed, avoiding potential stresses that could result in structural failure.

In comparison, other methods such as cross bracing and diagonal ties, while effective in some contexts, may not be classified as "acceptable" for the specific internal erection scenario being considered. Additionally, options like weight anchoring and support beams or vertical strutting and external supports might not provide the necessary stability required in an internal erection environment. Therefore, the collar and yolk combination stands out as a reliable method for this particular application.